Identification of drug leads targeting SOD1 dissociation for the treatment of ALS

鉴定用于治疗 ALS 的靶向 SOD1 解离的药物先导物

• 批准号: 8410563
• 负责人: Elizabeth A Proctor
• 金额: $ 3.05万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-12-01 至 2013-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8410563
• 关键词: Accounting; Affect; Age; American; Amyotrophic Lateral Sclerosis; Binding; Binding Sites; Biological Assay; Cessation of life; Complex; Computing Methodologies; Cuprozinc Superoxide Dismutase; Databases; Development; Disease; Disease Progression; Dissociation; Docking; Drug Design; Enzymes; Equilibrium; Erythrocytes; Etiology; Event; Frequencies; Genes; Goals; Human; Hybrids; Hydrogen Bonding; In Vitro; Individual; Knockout Mice; Lead; Ligand Binding; Ligands; Link; Modification; Molecular; Motor Neurons; Mutation; Nature; Neurodegenerative Disorders; Pathway interactions; Pharmaceutical Preparations; Phosphorylation; Population; Post-Translational Protein Processing; Prevention; Process; Protein Dynamics; Proteins; Research Personnel; Research Project Grants; SOD1 gene; Sampling; Site; Speed; Structure; Techniques; Testing; Therapeutic; Thermodynamics; Time; Toxic effect; Variant; Work; base; design; dimer; drug candidate; gain of function; insight; molecular dynamics; monomer; mutant; neuron loss; neurotoxic; novel; prevent; public health relevance; research study; residence; screening; simulation; small molecule; virtual

DESCRIPTION (provided by applicant): Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease affecting over 5500 Americans each year. Onset of ALS usually occurs between ages 55 and 65, and the disease is invariably fatal. ALS occurs in both familial and sporadic variants; the only known cause of ALS is mutation to the SOD1 gene, which is present in twenty percent of familial cases. This mutation causes the SOD1 protein to misfold and aggregate, creating toxic plaques that are believed to cause motor neuron cell death. The long-term goal of this work is to identify the mechanisms of SOD1 aggregation, and prevent aggregation by the binding of designed small molecule drugs. A key step in the aggregation of SOD1, a homodimeric metallo-enzyme, is the dissociation of the dimer. Prevention of dissociation of SOD1 could prevent the formation of aggregates, and therefore prevent motor neuron death. In addition to mutation, post-translational modifications to SOD1 also cause increased dissociation of the dimer. Post-translational modification occurs in both mutant and wild-type SOD1, and could provide a link between familial and sporadic forms of ALS. Unlike mutation, modifications cause significant change in the structure of SOD1. Because post-translational modifications are present at high frequency in humans, with approximately fifty percent of SOD1 being modified, any drugs designed for SOD1 will need to take into account these structural changes. The aims of this research project are: (1) to determine the mechanism of dimer destabilization in post-translationally modified SOD1, and (2) to identify small molecules capable of binding to both post-translationally modified and unmodified SOD1 to stabilize the dimer interface. We hypothesize that modifications destabilize the dimer by disrupting interactions across the dimer interface. Further, we hypothesize that a small molecule bridging the two monomers can stabilize the dimer and rescue from the effects of mutation and modification. To achieve specific aim 1, we will perform Discrete Molecular Dynamics (DMD) simulations of modified and unmodified species of SOD1 in order to gain insight into the thermodynamic and structural effects of modifications. To achieve specific aim 2, we will identify candidate drug-binding pockets near the dimer interface of SOD1 and use a novel hybrid virtual screening technique incorporating DMD simulations to evaluate the binding of drug molecules to the identified pockets. If our proposed aims are achieved, we will (1) contribute a possible etiology and molecular mechanism for SOD1 toxicity in ALS linking familial and sporadic cases, and (2) identify new lead compounds toward the treatment of ALS and introduce a novel virtual screening method for the computational assay of small ligand binding incorporating ligand-protein dynamics as well as energetic contributions. Using the results of this proposal, we may build a clearer description of the determinants of SOD1 stability. This work will provide a description of a possible molecular etiology common to familial and sporadic ALS, as well as present a new strategy for the discovery of therapeutics.

描述（由申请人提供）：肌萎缩侧索硬化症 (ALS) 是一种进行性神经退行性疾病，每年影响超过 5500 名美国人。 ALS 发病通常发生在 55 岁至 65 岁之间，并且这种疾病总是致命的。 ALS 既有家族性变异，也有散发性变异； ALS 唯一已知的原因是 SOD1 基因突变，该基因存在于 20% 的家族性病例中。这种突变导致 SOD1 蛋白错误折叠和聚集，产生有毒斑块，据信会导致运动神经元细胞死亡。这项工作的长期目标是确定 SOD1 聚集的机制，并通过设计的小分子药物的结合来防止聚集。 SOD1（一种同型二聚体金属酶）聚集的关键步骤是二聚体的解离。防止 SOD1 解离可以防止聚集体的形成，从而防止运动神经元死亡。除了突变之外，SOD1 的翻译后修饰也会导致二聚体解离增加。翻译后修饰发生在突变型和野生型 SOD1 中，并且可以提供家族性和散发性 ALS 之间的联系。与突变不同，修饰会导致 SOD1 结构发生显着变化。由于翻译后修饰在人类中频繁出现，大约 50% 的 SOD1 被修饰，因此任何针对 SOD1 设计的药物都需要考虑这些结构变化。该研究项目的目的是：(1) 确定翻译后修饰的 SOD1 中二聚体不稳定的机制，以及 (2) 鉴定能够结合翻译后修饰和未修饰的 SOD1 以稳定二聚体界面的小分子。我们假设修饰通过破坏二聚体界面上的相互作用来破坏二聚体的稳定性。此外，我们假设桥接两个单体的小分子可以稳定二聚体并免受突变和修饰的影响。为了实现具体目标 1，我们将对 SOD1 的修饰和未修饰物种进行离散分子动力学 (DMD) 模拟，以深入了解修饰的热力学和结构效应。为了实现具体目标 2，我们将识别 SOD1 二聚体界面附近的候选药物结合口袋，并使用结合 DMD 模拟的新型混合虚拟筛选技术来评估药物分子与识别的口袋的结合。如果我们提出的目标得以实现，我们将（1）贡献 ALS 中 SOD1 毒性的可能病因学和分子机制，将家族性病例与散发病例联系起来；（2）确定用于治疗 ALS 的新先导化合物，并引入一种新型虚拟筛选方法用于结合配体-蛋白质动力学以及能量贡献的小配体结合的计算测定。利用该提案的结果，我们可以对 SOD1 稳定性的决定因素进行更清晰的描述。这项工作将描述家族性和散发性 ALS 常见的可能分子病因，并提出发现治疗方法的新策略。